1. Field of the Invention
The invention pertains to the field of wrenches. More particularly, the invention pertains to a wrench with a rotating ratcheting open end.
2. Description of Related Art
Wrenches are commonly used for tightening, loosening, or removing rotary fasteners from threaded shafts. Open end wrench heads are commonly angled at 15° with respect to the wrench shaft so that when the user has only limited space for the rotation of a hexagonal fastener in the range of greater than 30° but less than 60°, by rotating the fastener about 30°, flipping the wrench over, and rotating again about 30°, the user can rotate the hexagonal fastener by the 60° necessary to slide the wrench around the next pair of sides and rotate the hexagonal fastener further.
Closed-end wrenches and socket wrenches commonly include a ratcheting mechanism such that the head of the wrench locks with respect to the wrench shaft when the wrench is turned in one direction but rotates freely in the other direction. This allows the user to turn the rotary fastener as many times as needed in one direction without taking the wrench off the fastener.
There are situations, however, such as in hydraulic lines or certain confined spaces, where a rotary fastener is located such that only an open end wrench may be used and only a limited range of rotation (less than 30°) of the wrench is possible.
There have been a number of attempts to create a wrench with a continuously rotatable ratcheting open end, including U.S. Pat. No. 2,376,575, entitled “Ratchet Wrench” and issued May 22, 1945 to Cronan, U.S. Pat. No. 2,401,128, entitled “Open End Ratchet Wrench” and issued May 28, 1946 to Anderson, U.S. Pat. No. 2,551,669, entitled “Ratchet-Pawl Retaining Structure” and issued May 8, 1951 to Hale, U.S. Pat. No. 2,851,914, entitled “Open End Ratchet Wrench” and issued September 16, 1958 to Zeckzer, and U.S. Patent Application Publication No. 2006/0137492, entitled “Reversible Ratcheting Open-End Wrench” by Melos and published Jun. 29, 2006. In each of these designs, a non-rotating support structure extends to the tip of the open end of the wrench such that once the rotating slot portion of the wrench rotates away from the non-rotating slot portion, the wrench head essentially becomes a closed-end head until the rotating portion rotates the full 360°. Thus, it is only possible to slide the wrench head back off the rotary fastener after each full rotation of the fastener. Each of these designs requires a wider head than a standard open-end head to support the circular rotating portion of the head, which prevents usage of the wrench in certain confined spaces. Each of these designs also requires at least two pawls in order for at least one pawl to be engaged with the ratchet teeth of the wrench head at all times.
The designs of U.S. Pat. No. 2,521,419, entitled “Ratchet-Actuated Open-End Wrench” and issued Sep. 5, 1950 to Sellers and U.S. Pat. No. 6,155,140, entitled “Ratchet Wrench” and issued Dec. 5, 2000 to Tsai use wider openings for the stationary parts of the open end, which provides a range of angles over which the wrench can be slid off the fastener, but again, two pawls and a wider head are required in order for the head to be continuously rotatable.
The above-mentioned patent documents are hereby incorporated by reference herein.